The invention relates to a device and a method for the trouble-free drawing-off or casting of hot melts which are kept in storage until they are converted into a casting.
In high-temperature technology, the handling of liquid melts is a task which is frequently encountered. The handling of liquid melts at temperatures above 1000° C. is to be found for example in foundry practice, in the glass industry or in high-temperature gasification in accordance with the THERMOSELECT process, to mention just a few examples. Basically the melts are stored in melting furnaces, which are provided with an electric or external heating system, and are then cast or drawn-off for further processing (continuous casting, surface casting, dead-mould casting or similar).
In the case of high-temperature gasification according to the THERMOSELECT process of different types of waste, such as domestic, industrial or special waste, unsorted waste is for example introduced into a reactor. The inorganic constituents, e.g. iron, are melted at temperatures of approx. 2000° C. The mineral melt is then passed over a cooled copper ring and granulated with H2O. Above the cooling ring are arranged burners in order to guide the melt securely into the granulating system.
What is problematic about these methods, especially the THERMOSELECT process, is the formation of so-called “plugs” at the outflow. Due to the formation of such solidified melt plugs at the outflow from the furnaces, very often interruptions in or problems with operation occur. For example in the THERMOSELECT process, where there are large proportions of iron, the melt, which solidifies as it flows out, begins after some time to adhere to the cooling ring. A plug is formed. Only after the plug has been manually removed can the process of casting be continued.